HOLO-KROME 76484 M20-2.5 X 40mm 소켓 캡 나사 | 육각 소켓 드라이브 | 합금강 열처리 블랙 옥사이드 (10개/팩)

The black oxide finish on these has held up through repeated assembly and disassembly in my tooling setup without any flaking. The hex socket drive seats a wrench cleanly every time, no wobble or stripped corners. For the price per piece, these are a solid deal for precision work.

These screws fit perfectly into my jig setup, and the hex socket drive grabbed cleanly without any stripping. The thermal black oxide coating looks sharp and consistent across all ten pieces, which matters when they're visible on a machine.

Installed these into a jig for a production run and the black oxide finish held up great against any minor surface rust. The hex socket drive seated perfectly with my wrench, no stripping at all.